Grease



tente pr. 19, 1938 STATES.

PATENT OFFICE amass No Drawing. Application August 9, 1934,

' Serial No. 739,107

2 Claim.

This invention relates to the preparation of greases, and moreparticularly to greases containing a grease base of saponified oxidizedpariit wax.

g I is well recognized that oxidized paraflin wax contains acids andsaponifiable esters. It has heretofore been proposed to separate theacid content of the oxidized wax, and to utilize the separated acids forthe preparation of soaps in the manufacture of lubricants. It has alsobeen proposed to incorporate in a lubricating oil a small proportion ofoxidized paraffin wax to increase the adhesiveness of the liquid oil.

We have discovered that by saponifying oxiis olized paramn wax, whichcontains a sufiicient proportion of saponifiable matter, a suitable basematerial for the preparation of greases is obtained. This base materialconstitutes a substitute for the fats and fatty acids ordinarilyemployed in greases, and efiects material economy by thus replacing inwhole or part the more expensive fats and fatty acids. This alsoobviates the additional processing steps inherent in the former practicewhere the acids are separated from oxidized paramn wax, as well asenabling the bulk of the oxidized wax to be employed. The invention isdistinguished from-the former practice of adding a small quantity ofoxiwax to a lubricating oil, in that the oxidized m) wax is saponified,and then is employed as a base material for the preparation of a greaseas distinguished from an oil.

In accordance with the present invention, parw wax is air blown atelevated temperatures, 35 generally in excess of 250 F., for a period oftime until a substantial content of saponiflable matter is formed in thewax by oxidation. A predetermined quantity of the oxidized wax is thenintroduced into a conventional grease mak- M ing kettle, and aproportionate quantity of an alkaline saponifying agent, such as lime,caustic soda or mixtures thereof, is added. The mass is agitated atelevated temperatures until the added alkali has neutralized andsaponifled the oxidized M wax to form soaps in admixture with theunsaponiflable content of the oxidized wax. The agitation may beaccomplished by mechanical stirring, air blowing, or both, during thesaponiflcation treatment. As the batch begins to o thicken, alubricating oil is added from time to time to keep the contents of thevessel sufliciently fluid to prevent stalling of the stirring device andaflord proper agitation. Additional quantities of lubricating oil are,ilnally added to bring the batch to the desired consistency.

The following is a specific example of the method of producing thegrease base of the present invention. A charge of parafiin wax wasmaintained at a temperature of about 295 to 330 F., while air wasintroduced in fine streams at the bottom of the vessel. The oxidationwas allowed to proceed for a period of approximately nine hours,although a somewhat shorter or longer oxidation time can be employed.The properties of the material throughout the latter From the aboveoxidized wax, blown for nine hours and having a saponification value of204, lime, soda, and mixed lime and soda grease bases were prepared'byadding substantially the chemical equivalent amounts of alkalinesaponifying material to batches o; the oxidized wax in'a grease kettle,and agitating while heating by the introduction of steam to the steamjacket of the kettle for approximately an hour. The resulting greasebases were employed in the manufacture of greases by mixing alubricating oil with the bases in the grease making kettle, whileheating and agitating, the grease base being substituted in whole or inpart for-the customary tallow or other fat or fatty oil asconventionally employed.

By way of example, a lime base grease was prepared by adding apredetermined amount of the oxidized paraflin wax prepared as outlinedabove to a previously cleaned grease kettle. To the kettle was thenadded a suspension of lime and water, and the contents of the kettlewere stirred while heat was applied from the steam jacket oi. thekettle. After the batch began to thicken, suflicient pale lubricatingoil was added to keep the contents of the kettle sufficiently fluid forproper agitation. Additional quantities of oil were added from time totime until the desired consistency was attained. The proportion of wateradded in the lime suspension, or in addition thereto, was considerablyin excess of that ordinarily employed in the manufacture of ordinary cupgrease, and was suflicient to provide at least 10% by weight of water intheflnished product, which enabled a grease of smooth texture.to beobtained. A soda base greeserlas prepared in a similar manner, exceptthat in this case the water content of the finished prodnot was around4% by weight or above. The proportions of soap to lubricating oil mayvary within wide limits according to the type and characteristics of thegrease desired, and may approximate the proportions customarily employedwhere tallow or other usual fats or fatty oils are used.

While satisfactory greases may be prepared by substituting thesaponifled oxidized parafiln wax in whole for the fats and fatty acidscustomarily employed, it is to be understood that various proportions offats or fatty oils of animal or vegetable origin can be included. Othermetallic base greases, such for example as a lead base grease by theemployment of litharge, can be prepared from the oxidized parafiln waxin the manner of the lime and soda base greases described above. Thehardness and consistency of the greases can be controlled by variationsin the proportions of lubricating oil and soap, as is well understood inthe grease making art.

' atlases Obviously many modifications and variations of the invention,as hereinbefore set forth, may be made without departing from the spiritand scope thereof, and therefore only such limitations should be imposedas are indicated in the appended claims.

We claim:

1. A lubricating grease comprising essentially a mineral lubricatingoil, and saponifled crude oxidized parafiin wax consisting of soaps ofcaponiflable constituents of the oxidized paraffin wax admixed withnon-saponifiable constituents remaining therein.

2. A lubricating grease composition consisting essentially of minerallubricating oil and saponified crude oxidized paraffin wax, saidsaponifled crude oxidized paraffin wax containing a mixture ofunsaponifiable constituents present in the oxidized wax and one or moresoaps, oi the class oi. lime and soda, of the saponiflable constituents.

BENJAMIN GALLSWORTl-IY. JOSEPH R. SCANLIN.

